Engineering:Drawbar (machine tool)

A W-type external-thread collet (red) being pulled into its spindle seat (green) with a drawbar (blue), clamping and then releasing a shaft.

A drawbar or spindle drawbar is a clamping mechanism for toolholders on machine tools. The toolholder or machine taper itself is held by the draw bar and applies force to the spindle, especially when spinning at low speeds.